Factory solar plus portable

[Leslieotr]

We have the Zamp 160 portable panels also. I had the same question and would love to hear how your panels attached to the truck work. Sounds like a reasonable solution.

Thanks,
Leslie

[WestieHouse]

Originally Posted by Leslieotr

We have the Zamp 160 portable panels also. I had the same question and would love to hear how your panels attached to the truck work. Sounds like a reasonable solution.

Thanks,
Leslie

I have a trip to Death Valley planned for February during which I will deploy this approach of mounting portable Zamp panels to my TV (Jeep GC Eco Diesel) roof rack. This will be a test in preparation for an Alaska trip this summer where I expect to boondock frequently. I will post my results here in late February.

[AirstreamCSH]

Originally Posted by WestieHouse

Interesting discussion. After considering whether to invest in an add-on roof solar system (my 2015 23 FB is supposedly prewired for it, but I understand it is not the ideal setup), I purchased 160 watt Zamp portable unit. Though bulky and at 37lbs adds to my limited payload, I saved lots of money and gained flexibilty regarding shaded camps, etc. It works fine for recharging my two Group 24 AGM batteries within a few hours on good days, even here in the PNW. But the problem was how to break camp after a night of boondocking and still have recharged batteries at our next camp later that day?



My plan is to fasten my Zamp panels on the flat roof top ski rack (no gear accessories) using two 1 inch nylon straps (each placed diagonally corner to corner). I will run the power cord down the back of my tv and make the usual battery connection. Slack cord will be stored under cover in my LPG tank area. I will cushion the panels with foam used for carrying boats on the rack. The Controller will be visible through my moonroof and hang above the glass.



Everything measures up well and I plan to do this for the first time during a trip from Orange County to Death Valley and Lake Havasu in February.



Has anyone attempted this approach? Any thoughts concerning this approach? As with any roof top rack items (we have extensive experience transporting bicycles, skis, kayaks, and a box) secure and balanced fastening is critical. Other thoughts are welcome - I prefer learning from your mistakes, if there were any!



I appreciate the wisdom of folks on this forum!

I used this method while,boondocking to get the solar panels off the ground. Gave some thought to how I’d mount it while driving and tried a few ideas. Problem I ran into was the uplift problem in that the suitcase Zamp design wasn’t designed for that pressure. My solution was to affix a 1/2 plywood board to the bottom with 1/4” stainless bolts and nylon lock nuts following a 1” fender washer. Then attached a half round 4” pipe insulation as a wind shield on the leading edge to prevent air from getting in between the board and Zamp to prevent uplift. Further, the Zamp was mounted at an angle with the leading edge on the roof tucked against the roof rack and the trailing edge resting on the rearmost roof rack. Unbolt thru to crossbar. Wire snaked as expected to a Zamp plug I had mounted into the side of the battery box. Downside is you lose visibility to the charge controller but by this point I had an unwieldy solar panel that required two people to get into place due to weight and size before the whole plywood design.

After these machinations I concluded that in the event I failed to fully take into account wind sheer forces and this thing ripped off I’d have a heavy bulky half wing fly off at speed. Best case would be it smashed into the front of the AS and get caught around the propane tanks. Worst case would be it flew to the left or right before crashing into the window of another car.

So it came apart and I resolved to order parts from AM Solar to do a proper, engineered solution on the roof of the AS. Having seen the utility of the portable Zamp these past few years over fixed installs when parked in the shade, when I wire the rooftop units I will add a boat 1-2 switch controlling the Zamp port to allow for portable use.

YMMV

[WestieHouse]

...After these machinations I concluded that in the event I failed to fully take into account wind sheer forces and this thing ripped off I’d have a heavy bulky half wing fly off at speed. Best case would be it smashed into the front of the AS and get caught around the propane tanks. Worst case would be it flew to the left or right before crashing into the window of another car.....

YMMV[/QUOTE]

Although Death Valley may be an aptly named testing site, your analysis encourages me to reconsider this approach.
After all, changing ones mind offers evidence of its existence.

Thanks for sharing your experience!

[uncle_bob]

Originally Posted by AirstreamCSH

..... when I wire the rooftop units I will add a boat 1-2 switch controlling the Zamp port to allow for portable use.

YMMV

Hi

The "Zamp port" is nothing but a pair of wires to the battery. Yes, there's a connector with a cute cover and an inline fuse, but functionally it's just a chunk of wire. No different than a jumper cable or a wire to the 7 pin connector.

There is no need to put a switch on the Zamp port. If you have rooftop solar it hooks in through a totally different route.

Bob

[AirstreamCSH]

Originally Posted by uncle_bob

Hi

The "Zamp port" is nothing but a pair of wires to the battery. Yes, there's a connector with a cute cover and an inline fuse, but functionally it's just a chunk of wire. No different than a jumper cable or a wire to the 7 pin connector.

There is no need to put a switch on the Zamp port. If you have rooftop solar it hooks in through a totally different route.

Bob

The reason for a 1-2 switch is that when I eventually add a rooftop controller, if the portable is connected, it will fight the roof system one as only one can be used at a time.

[uncle_bob]

Originally Posted by AirstreamCSH

The reason for a 1-2 switch is that when I eventually add a rooftop controller, if the portable is connected, it will fight the roof system one as only one can be used at a time.

Hi

The two controllers will work it out on their own. The net result will normally be that the one with "more power" will win. No need for the switch.

Bob

[Shermy1987]

Charging with two charge controllers in almost every instance is perfectly OK. The idea that one controller will fight another controller is simply false. This idea comes from a lack of understanding on how a battery charges.

If a battery is in bulk charging stage, voltage varies and current is constant. If the first charger is charging at 13.7 volts. The second charger charges at 13.7 and current is added.

In absorbtion stage you may get some small variations if each charge controller has different parameters for constant voltage.

This goes beyond just two charge controllers. Theoretically you could charge with two charge controllers, your vehicles alternator and your generator. They will all be working. Your alternator won't be switching on and off. Neither will your generator.

Charging with 2 controllers is common in off grid systems. When one solar array has reached a maximum and another is added. Or say you have one array that gets heavily shaded in winter. You add a second array with a separate controller somewhere else where the sun is shining. Some controllers do talk to each other so they operate on the exact same charge algorithm. However this isn't a necessity and successful charging happens with mixed controllers.

If somebody is experiencing their portable charge controller fighting their TV charge controller. I'd like to see what controllers are being used and dig into how this could possibly be happening.

[uncle_bob]

Originally Posted by Shermy1987

Charging with two charge controllers in almost every instance is perfectly OK. The idea that one controller will fight another controller is simply false. This idea comes from a lack of understanding on how a battery charges.

If a battery is in bulk charging stage, voltage varies and current is constant. If the first charger is charging at 13.7 volts. The second charger charges at 13.7 and current is added.

In absorbtion stage you may get some small variations if each charge controller has different parameters for constant voltage.

This goes beyond just two charge controllers. Theoretically you could charge with two charge controllers, your vehicles alternator and your generator. They will all be working. Your alternator won't be switching on and off. Neither will your generator.

Charging with 2 controllers is common in off grid systems. When one solar array has reached a maximum and another is added. Or say you have one array that gets heavily shaded in winter. You add a second array with a separate controller somewhere else where the sun is shining. Some controllers do talk to each other so they operate on the exact same charge algorithm. However this isn't a necessity and successful charging happens with mixed controllers.

If somebody is experiencing their portable charge controller fighting their TV charge controller. I'd like to see what controllers are being used and dig into how this could possibly be happening.

Hi

....errrr ..... not so much. There are lots of threads on why this is a problem.

Once they both hit 13.7V and you get a slightly higher voltage on one (which you will) the current drops. When it drops past the set threshold, the converter will fold back into float mode and stay there.

The same voltage offset = current imbalance problem is an issue even without the fold back. If you want them both to do the job, you need to keep one in slave mode. It stays in constant current mode and simply duplicates the current delivered by the device that is set to 13.7V. If you take a look at how industrial power systems do this, they all work that way.

Bob

[Shermy1987]

Originally Posted by uncle_bob

Hi

....errrr ..... not so much. There are lots of threads on why this is a problem.

Once they both hit 13.7V and you get a slightly higher voltage on one (which you will) the current drops. When it drops past the set threshold, the converter will fold back into float mode and stay there.

The same voltage offset = current imbalance problem is an issue even without the fold back. If you want them both to do the job, you need to keep one in slave mode. It stays in constant current mode and simply duplicates the current delivered by the device that is set to 13.7V. If you take a look at how industrial power systems do this, they all work that way.

Bob

Like I said. Provide us the models of controllers that are having the problem you're stating along with the percentage of time lost to reach full charge. It would be great to have a list of these on the thread.

There's lots of assumptions being thrown around. Who's showing the evidence?

[uncle_bob]

Hi

Every non-networked non-slaved controller out there has the problem. A list of "controllers with the problem" is simply a list of every controller made. There is no value in listing every controller on the market. The only ones that I know of that can be set up *not* to have the problem are the Victron units when run with a networking controller to slave them together. I'm sure there are others out there, but they have the same gotcha - you need the networking controller and the software in it to get things to work. That runs the price up.

Bob

[PeterDB]

We have 200 watts of solar on the roof, looks like an AM Solar installation, cant tell for sure, we’re the second owners with the solar added by the first owner (thank you whoever you are!) along with group 27 AGMs somehow stuffed into the stock battery box. This provides ample power in most conditions. We also have a portable 100w panel from InstaPark called a Mars-100. I bought it from Amazon 5 or more years ago for a ridiculously low price and used it as our primary recharging source when we had a t@b camper. Now I use it as backup primarily when the AS19 is parked in the shade. The portable panel has its own charge controller and I wired up a female 7-way receptacle such that I can just plug it into the trailer 7-way connector. I bought 50 feet of 10-gauge landscape lighting wire to allow putting the panel in the sun. I’m thinking of buying 50 feet of 6-gauge flexible welding wire to replace the landscape wire but I haven’t gotten around to it. As it is, I can still get adequate charge from this setup so replacing the wire hasn’t been a priority. I guess I’d do it if the portable panel was my primary charging source. I did use the 6-gauge welding wire to power the truck’s 7-way receptacle for better en route charging but that’s another story. Anyway, my observation is as uncle_bob suggests, charging comes from which ever panel outputs the most power at the moment. With roof-mounted solar I’m not sure if this or the TV charges while towing. I guess it depends on the charge state of the TV battery. The TV regulator sees the combination of the TV and trailer batteries.

[Shermy1987]

All I can say is that the solar business my family has ran for 20 years hasn't shown much evidence of this. Installing up to 5 solar controllers is normal practice. When an array exceeds what a single controller can provide, another is installed and so on. Most controllers seem to be limited to about 60 to 80 amps.

People have the most problemsl when they piggy back controllers. This should never be done. The controllers need to be connected directly to a bus bar or the battery. Only quality controllers are ever used (morningstar, outback power etc) and no they don't synchronise with each other.

The only thing that ever happens is one controller will turn off before the other. This is always at a time when absorbtion is almost complete and the current from one array is sufficient to provide maximum allowable amps anyhow. 20 years and hundreds of installs is pretty good evidence to show that many controllers work just fine in tandem.

[Mattirs]

https://www-altestore-com.cdn.amppro...in-parallel%2F

Found this on the alte store site where two controllers are wired in parallel.

(Hope the link worked my first try. If not search alte store two controllers in parallel)

Thanks
Matti

[uncle_bob]

Originally Posted by Shermy1987

All I can say is that the solar business my family has ran for 20 years hasn't shown much evidence of this. Installing up to 5 solar controllers is normal practice. When an array exceeds what a single controller can provide, another is installed and so on. Most controllers seem to be limited to about 60 to 80 amps.

People have the most problemsl when they piggy back controllers. This should never be done. The controllers need to be connected directly to a bus bar or the battery. Only quality controllers are ever used (morningstar, outback power etc) and no they don't synchronise with each other.

The only thing that ever happens is one controller will turn off before the other. This is always at a time when absorbtion is almost complete and the current from one array is sufficient to provide maximum allowable amps anyhow. 20 years and hundreds of installs is pretty good evidence to show that many controllers work just fine in tandem.

Hi

Gee..... one shuts down and the other one is the only one supplying current. Sounds a lot like "they stop working together".

The point this happens is when they go out of constant current mode....

Bob

[turk123]

Found this real-world video showing what happens hooking two charge controllers together.



https://www.altestore.com/blog/2016/...-parallel/amp/

[Mattirs]

Originally Posted by turk123

Found this real-world video showing what happens hooking two charge controllers together.



https://www.altestore.com/blog/2016/...-parallel/amp/

Great minds think alike [emoji2]

See post 34

The alte store have a great set of teaching and exploring videos.

[Airdream99]

Originally Posted by JMynes

Wow. Seems to me it would have been easier to rewire the A-Frame connector to the panel side of the controller. Plug your portable panel (without a built-in controller) into the A-Frame and all panels work together seamlessly.

I would love to see some comments on this approach. I have a 27FB and the charge controller is right there under the front bunk not 2 feet from the A-frame plug. I have factory solar on the roof (2 panels -160 watts) with one open port in the roof top Z-amp collector plug. How would adding a third panel (portable) directly to the input side of the charge controller be any different than adding a third panel to the roof?

[Shermy1987]

Originally Posted by Airdream99

I would love to see some comments on this approach. I have a 27FB and the charge controller is right there under the front bunk not 2 feet from the A-frame plug. I have factory solar on the roof (2 panels -160 watts) with one open port in the roof top Z-amp collector plug. How would adding a third panel (portable) directly to the input side of the charge controller be any different than adding a third panel to the roof?

It would be the same. You would have to make sure the new solar panel matched in voltage and cell number. The wiring and charge controller would also have to be able to handle the combined current of the old panels plus the new panel.